Water-tube boiler



L. STEINMLLER WATER TUBE BOILER sept. 1s, 192s. 1,684,6"1

Filed Sept. 10. 1925 @Zia/0% Mr/wy.

Patented Sept. 18, 1928.

UNITED STATES 1,684,691 PATENT OFFICE.

LEBRECHT STEINMLLER, 0F GUMMERSBACH, GERMANY, ASSIGNOR TO lFIRMA L. & C. STEINMLLER, OF GUMMERSBACH, RHEINLAND, GERMANY.

WATER-TUBE :BOILEI:k

Application filed September 10, 1925, Serial No. 55,587, and in Germany July 11, 1925.

This invention relates to improved means for protecting the drums, and more particularly the upper drums, of water tube boilers from the strong or direct action of the hot gases or flames. In water tube boilers Working at high pressures,'the metal of the drum walls is relatively thick and under the action of the hot gases the outer skin is very highly heated Whilst the inner skin is substantially at the temperature of the water or steam, whereby considerable internal strains are caused which lead to curvature or Wrinkling of the boiler drum. The obstruction offered by the Water tubes which enter the drum in spaced rows makes the insulation of the drum IWalls difficult and the object of the present invention is to overcome this difficulty and give the greatest possible degree of protection to those parts of the drum wall where the water tubes enter the drum. At the same time the means used must not interfere with the ready removal of damaged tubes, such as would be the case if an outer protecting drum were employed.

According to this invention strings of contiguous refractory blocks are supported in the spaces between adjacent rows of Water tubes and are held close to the wall ofthe drum. The refractory blocks are supported preferably on relatively flexible stringers, such as curved rods, Wire ropes, chains or the like, so that any desired string of blocks may be readily inserted or removed without dismantling the entire protective covering of the drum Wall. The blocks protect the greater part of the drum Wall occupied by the tube bank, but there is still left uncovered the spaces between the separate tubes of each row. At these parts of the drum there are formed dead spaces in Which there is little or no movement of the furnace gases and these small bodies of furnace gases being in close contact with the Water tubes are not at a high flame temperature, so that they do not raise the temperature of the outer skin of the drum and in fact function as fairly efficient non-conductors. It may thus be considered that the entire drum occupied by the tube bank is effectively protected, even Vthough the refractory covering only extends over a major part of the section ,of drum wall occupied vby the tube bank.

In order still further to protect this section ofthe drum wall occupied by the tube bank, both as regards the section covered by the refractory blocks and that left uncovered, I lnterpose an additional protective layer between the blocks and the drum wall. This layer preferably consists of asbestos plates or tiles, formed as rectangular pieces with quarter circle sections cut out at their corners to nest around the exterior of the water tubes. These asbestos tiles are clamped or held in place by the refractory blocks and extend beyond the face of the blocks to cover the part of the drum wall at the tube bank where the same is left uncovered by the blocks. i

The part of the drum lwall laterally of the tube banks and which is also exposed to the direct flame action, is also covered by a protective layer, the refractory blocks (if which are threaded on the same stringers as those which support the blocks located between the rows of tubes, but these laterally arranged blocks are wider than the blocks between the tube rows by an amount equal to the diameter of the tubes, so that in this latter section of the drum,`the entire wall is covered with the refractory blocks and moreover the lateral spaces, or more correctly the ends of the spaces, between the rows of blocks lo-. cated between the tubes are closed off. rlhis has the effect of preserving the dead nature of the small intertubular spaces mentioned above.

The invention is illustrated by way of example in the accompanying drawings, in two modifications. f In these drawings:

Fig. 1 is a cross section of the drum of a water tube boiler with my improved protective layer applied.

Fig. 2 is a longitudinal Section of the.

same.

Fig. 3 is a cross section of a modified form, and Fig. 4 is a longitudinal section of the same.

Fig. 5 is a plan view of the asbestos or like tile which is interposed between the refractory blocks and the drum wall.

Fig. 6 is a plan view of the tile which is used in the modified form of the invention disclosed in Figs. 3 and 4.-

In carrying the invention into effect 'as seen in Figs. 1 and 2, the bank of Water tubes is arranged in rows transversely to the axis of the Water drum and spaced as shown in Figure 2. Laterally of the upper drum a .of the water tube boiler, there are arranged bearer beams f close to the 'wall .Cil

of the drum and supporting the stringers e on which the refractory blocks are threaded. The refractory blocks d are shaped as arch bricks and the adjacent faces are in close contact when the blocks are strung on the stringer e. As can be seen in Fig.2, the' blocks d are of a width to pass easily between the rows of the water tubes b. Laterally of the bank of tubes and threaded on the same stringers, there are threaded wider blocks d1. The side faces of the blocks d1 contact with the faces of the blocks on the adjacent string, so that the entire drum wall laterally of the bank of tubes and up to the bottom face of the bearer f is covered with the refractory blocks. The bearers f for the stringers e also act as the bearers for the closing arches h for the top of the boiler. Between the blocks d and the drum wall there is interposed a further layer of protective material, such as asbestos. This layer is conveniently formed .of separate tiles shaped as shown' in Figure 5 so as to nest around the outer diameter of the water tubes and completely cover the exposed drum wall in this section. It will be seen that there are formed open spaces z' (Fig. l) bounded 4by the bricks d on two sides and by the adjacent tubes of one row on the other two sides. These spaces have open ends at the bottom thereof, but they are relatively deep and narrow, so that the gases cannot freely circulate therein and consequently remain practically stationary. For this reason these spaces may be considered as dead spaces as regards the circulation of the gases. What` gases there are in these spaces are cooled by the water tube walls and therefore these spaces act effectively as heat insulators to protect the walls of the drum.

In the modification illustrated in Fi s. 3 and 4, the bearers which support t e stringers e1 are locate some distance above the upper drum a. The bearers f1 for the cover arches h in this form are also clear of the side wall of the drum a, but in this form, as in the form shown in Figs. 1 and 2, these bearers are protected from the direct action of the flames by the refractory blocksl d3 and the arch bricks of the arch h. The speciall supporting bearers ,p for ,the stringers e1 may act as the supports for additional closing arches b The lblocks d2 in this form are threaded outside elevation, can be readily coupled to the chain when the same .is inl place. The interposed asbestos tiles c 1n this form means of bolts m and eye pieces n tov space between the rows of tubes and refract tory tiles located between said blocks and the wall of the drum and held in position by said blocks. v

2. In combination with a boiler drum, spaced rows of tubes entering said drum, and means for protecting the walls of said drum from direct flame action comprising strings of refractory `blocks located in the spaces between the rows of tubes, and refractory tiles located between said blocks and the wall of the drum and held in posi-y tion by said blocks, said tiles overhanging the blocks to cover the space between the adjacent tubes of each row.

3. In combination with a boilerdrum, spaced rows of tubes entering said drum, and means for protecting the walls of said drum from direct flame action comprising strings of refractory blocks located in the spaces between the rows of tubes, and rectangular refractory tiles located between said blocks and the wall of the drum, and held in position by said blocks, said tiles having their corners cut out to nest between four tubes.

4. .In combination with a` substantially cylindrical boiler drum having spaced rows of water tubes entering the lower walls of said drum, means for protecting the said lower walls from direct flame action comprising, bearer beams located on each side of saiddr'um and clear ofthe rows of water tubes, stringers supported from said bearers to embrace the drum between the 4rows of water tube-s, refractory blocks strung on said stringers and filling the s ace between the rows of watertubes, sai strin ers being themselves closed in by said bloc s, and refractory tiles located between said blocks andthe wall of the'drum and held in position by said blocks.

5. In combination with a substantially cylindrical boiler drum having space d rows of water tubes entering the lower walls of said drum, means forl rotecting the said l I n lower walls from direct ame action comprisl bearers, stringers supported from said bearers to embrace the drum 'betweenthe rows of water` tubes.l refractory blocks strung on said stringers and filling the space be tween the rows of. water tubes and closing in the bottom of said arch supporting bearers and stringers to protect same from the direct flame action, and refractory tiles located between said blocks and the wall of the drum and held in position by said blocks.

6. In combination with a substantially cylindrical boiler drum having spaced rows of water tubes entering the lower walls of said drum, means `for protecting .the said lower walls from directflame'action comprising, bearer beams located on each side of 'said drum and cleary of the rows of water tubes, stringers supported from said bearers, refractory blocks strung on said stringers and filling the -space between the rows of tubes, wider blocks also strung on said stringers and located laterally of the rowsof tubes, and refractory tiles located between said blocks and the wall of the drum and held in position by said blocks.

'7. Incombination with the substantially cylindrical upper vdrum of a water tube boiler having spaced rows of water tubes entering the lower walls of said drum, means for protecting the said lower walls from direct flame action comprising a .c hain, refr-actor blocks strung on said cham to Vform a rlng of contiguous blocks and means for supportino' the ends of said chain so that the said tblocks hang in the space betweentwo adjacent'rowsof tubes and con- 'tact with the ,drum'fwalh and refractory tiles located between lsaid` blocks and the wall of the drum and held' in position by said blocks, said tiles overhanging the blocks to cover the space between the adjacent tubes of each row. l

8. In combination with-a substantially cylindrical boiler drum having watertubes entering the lowervwalls of saidA drum, means for protecting'thesaid lower walls fromrdirect flame actionicomprising contiguousv ref fractory blocks located between the rows of.

tubes, chain stringers for said blocks, boltfl v and eye fixtures 0neach blockof va string of y-0 contiguous blocks, said fixtures being attached to the links of the chain, 'bearer beams for the ends of said 'chains and located at each side of and above the drum and closing arches'supported o'n said bearers, and rectangular refractory tiles located between said blocks and the wall of the drum and held in position by said blocks, said tiles having their corners cut out to nest between four tubes.

DR. LEBRECHT STEINMLLER. 

